Ship propulsion system having a pump jet

ABSTRACT

The present invention relates to a ship propulsion system (S) having a pump jet (P), which comprises a pump housing (G) and a drive motor, wherein a rotor ( 2 ) of an impeller of the pump jet (P) has a rotational axis (B) which is not aligned with a control axis (A) of the pump jet (P).

The present invention relates to a ship propulsion system having a pump jet according to EP 0 612 657.

Such ship propulsion systems are known from practice, and they contain a pump jet as main and/or auxiliary drive. The energy supply occurs, for example, on one hand, via a gear system, with, as desired, a diesel, electric or hydraulic motor connected before it, or directly via an impeller shaft by means of a motor arranged outside of the drive. The electric motors being used are conventional electric motors.

Although such ship propulsion systems are extremely advantageous constructions, the present invention has and achieves the goal of a further improvement, particularly with regard to simplifying the construction, efficiency of the drive, and broadening of the range of possible applications.

For this purpose, the invention creates a ship propulsion system with a pump jet, which contains a pump housing and a drive motor, where a rotor of an impeller of the pump jet contains a rotational axis which is not aligned with a control axis of the pump jet.

This design can advantageously be further developed so that the rotational axis of the rotor is offset with respect to the control axis of the pump jet, where, furthermore, it is preferred for the rotational axis of the rotor and the control axis of the pump jet to be parallel. Alternatively or additionally, it is possible to provide advantageously that the rotational axis of the rotor and the control axis of the pump jet are mutually inclined, where, furthermore, the rotational axis of the rotor and the control axis of the pump jet intersect particularly at one point.

Moreover, it is possible to provide advantageously that the drive motor is an electric motor which is set on the pump housing or integrated partially therein.

This design can advantageously be developed further in that the electric motor is an asynchronous motor, synchronous motor or permanent magnet motor, and/or in that between the electric motor and parts that transfer force to the impeller, such as teeth, roller bearings and/or shafts are provided.

An additional preferred embodiment is one in which the drive motor is a magnet motor integrated in the pump housing.

Alternatively, the invention creates a ship propulsion system with a pump jet, which contains a pump housing and a drive motor, where the drive motor is a high-temperature superconducting motor integrated in the pump housing.

It is preferred for the pump jet to be controllable all around.

Moreover, it is advantageous to provide that the magnet motor or high-temperature superconducting motor contains a rotor which is a component of an impeller of the pump jet.

An additional preferred embodiment consists in that the magnet motor or high-temperature superconducting motor contains a stator which is a component of a diffuser inner ring of the pump jet.

Another preferred embodiment consists in that the conveyance medium is also used particularly by itself as lubricant and/or coolant.

An additional preferred embodiment consists in that the drive of the pump jet is free of force transferring parts, such as teeth, roller bearings and/or shafts.

According to an additional preferred embodiment, deflection devices are provided which are arranged and/or designed in the inner space of the diffuser housing.

The deflection devices are preferably arranged and/or designed so that they eliminate turbulence from a water flow in the inner space of the diffuser housing and/or direct the water flow in such a way that water exits through a nozzle of the pump jet as much as possible without internal turbulence or in such a way that through individual nozzles a desired quantity of water exits per unit of time, particularly the same amount of water per unit of time and/or to the extent possible without internal turbulence, to achieve an optimal thrust effect of the pump jet. In addition or alternatively, it is preferred for the deflection devices to contain at least one shaping of the inner space of the diffuser housing. An additional preferred design in this connection consists in that the deflection devices contain an area with constant cross-sectional profile of the inner space of the diffuser housing, and/or in that the deflection devices contain an area with reduced cross-sectional profile of the inner space of the diffuser housing, and/or in that the deflection devices contain an area with enlarged cross-sectional profile of the inner space of the diffuser housing. Furthermore, the deflection devices can alternatively or additionally contain at least one guide vane in the inner space of the diffuser.

Additional preferred and/or advantageous embodiments of the invention result from the claims and their combinations, as well as from all the available application documents.

The invention is explained below using embodiment examples and in reference to the drawing, only as an example, where, in the drawing

FIG. 1 shows, in a schematic cross-sectional view, a first embodiment of a ship propulsion system with a pump jet,

FIG. 2 shows a schematic perspective view of the ship propulsion system with a pump jet of the first embodiment example,

FIG. 3 shows a schematic view of the ship propulsion system with a pump jet of the first embodiment example from below, that is, in the case of a pump jet attached to the hull of a ship, in the viewing direction towards the hull,

FIG. 4 shows a schematic view of the ship propulsion system with a pump jet of the first embodiment example from the inside towards the outside, that is, in the case of a pump jet attached to the hull of a ship, in the viewing direction away from the hull,

FIG. 5 shows, in a schematic view, a second embodiment example of a ship propulsion system with a pump jet, and

FIG. 6 shows, in a schematic view, a third embodiment example of a ship propulsion system with a pump jet.

With the aid of the embodiment and application examples described below and represented in the drawing, the invention is explained in further detail only as an example, that is, it is not limited to these embodiment and application examples or to the combination of characteristics within these embodiment and application examples. Method and device characteristics result in each case also analogously from the device and method descriptions.

Individual characteristics which are indicated and/or represented in connection with a concrete embodiment example are not limited to this embodiment example or the combination with the other characteristics of this embodiment example; rather, they can be combined, within the scope of technical feasibility, with any other variants, even if they are not discussed separately in the available documents.

Identical reference numerals in the individual figures and depictions of the drawing denote identical or similar, or identically or similarly acting components. With the help of the depictions in the drawing, those characteristics are also to be illustrated which are not provided with reference numerals, regardless of whether or not such characteristics are described below. On the other hand, characteristics that are contained in the present description, but not visible or depicted in the drawing, are also easily understandable to a person skilled in the art.

FIG. 1 is a schematic view of a ship propulsion system S with a pump jet P in a longitudinal cross section. The pump jet P contains a magnet motor M which is integrated in the flow housing or pump housing G, as drive motor with a stator 1 and a rotor 2. The rotor 2 is developed as an impeller outer ring I, and the stator 1 is integrated in a diffuser inner ring D of the pump housing G, which contains a diffuser housing 3 or is designed overall as such. The pump jet P also comprises a control motor 4, a control drive 5, with, for example, a spur wheel R, as well as a receipt transmitter 6 and a well plate 7.

FIG. 2 shows the ship propulsion system S with the pump jet P of the first embodiment examples in a schematic perspective view. FIG. 3 shows the ship propulsion drive S with a pump jet P of the first embodiment example in a schematic view from below, that is, in the case of a pump jet attached to the hull of a ship, in the viewing direction towards the hull. FIG. 4 shows the ship propulsion system S with the pump jet P of the first embodiment example in a schematic view from the inside towards the outside, that is, in the case of a pump jet attached to the hull of a ship, in the viewing direction away from the hull.

In particular, the ship propulsion system S is one that can be controlled all around, and whose pump jet P is mounted so it can be rotated by 360°. Besides the fact that the drive of the pump jet P occurs via a magnet motor M integrated in the pump housing G, it is also possible to provide, for the drive, a high-temperature superconducting or HTSC motor (not shown separately), where, in each case, the rotor 2 is more or less a component of the impeller I, and the stator 1 is an integrated component of the diffuser inner ring D. The consequence is that it is not necessary to use the conventional type of force transfer by means of drive motor, gear system and articulated shaft. As a result, a very compact drive unit is produced, which can be built into nearly any floating apparatus.

Due to the drive of the pump jet P with a magnet motor M or HTSC motor, no drive gear system parts, such as teeth, shafts, roller bearings are necessary. This has the consequence that the pump jet P can be classified as very low noise and low vibration, as well as presenting a high degree of efficiency. Furthermore, no oil filling for lubrication and cooling of rotating parts is necessary, which characterizes the pump jet P as oil free and low maintenance.

The particular resulting advantages are:

-   -   compact design     -   high degree of efficiency     -   very low noise     -   low vibration     -   oil free     -   low maintenance

By means of the control motor 4, the pump housing G, which contains the diffuser housing 3 or is designed overall as such, can be rotated in bearings 8 with respect to the well plate 7 about a control axis A precisely preferably by 360°, so that the nozzles 9 can be controlled in a desired direction, of which, in the cross-sectional view in FIG. 1, only one middle nozzle 9 b of three nozzles 9 a, 9 b and 9 c (see FIGS. 2, 3 and 4) can be seen.

Through a suction opening 10, water is drawn in by means of the rotor 2 into an inner space 11 of the diffuser housing 3. The water jet which thus flows into the inner space 11 of the diffuser housing 3 is deflected by the shaping of the inner space 11 of the diffuser housing 3, so that it exits through the nozzles 9 out of the pump housing G, precisely in accordance with the rotational position of the latter set by means of the control motor 4, in a desired direction. Because, as a result of the shaping of the inner space 11 of the diffuser housing 3, a deflection of the water flow, which enters through the suction opening 10 into the inner space 11 of the diffuser housing 3, is achieved, the diffuser housing 3 or the pump housing G is thus simultaneously also a deflection housing. The shaping, in the first embodiment example shown in FIG. 1, is bead like around the drive motor with the stator 1 in the diffuser inner ring D of the pump housing G, and the runner or rotor 2 as impeller outer ring I. The inner space 11 of the diffuser or deflection housing 3 with the specific shaping thus represents deflection devices 12.

To further influence the flow of the water drawn in through the suction opening 10 by way of the nozzles 9, as seen in the depiction of FIG. 4, a guide vane 13 is provided as a component of the deflection devices 12. Depending on the rest of the design of the deflection devices 12, several and/or differently positioned and designed guide vanes can be provided. The guide vanes, like the guide vane 13, serve the function of applying “turbulence removal” to and orienting the water flow with the deflection devices 12, water which enters or is drawn in through the inner space 11 of the diffuser or deflection housing 3, and which is made turbulent by the rapidly turning rotor 2, in such a way that, through the individual nozzles 9 a, 9 b and 9 c, in each case, for example, the same quantity or in general a desired quantity of water per unit of time exits to the extent possible without internal turbulence, to achieve an optimal thrust effect of the pump jet P.

According to the present invention, although this is not visible in the representation chosen for FIG. 1, the rotor 2 is provided with a rotational axis B which is offset with respect to the control axis A of the pump jet P; specifically, the rotational axis B is offset towards the rear, in reference to the drawing plane in which the control axis A is located; that is, farther away from the viewer. Such a type of offset is, however, clearly visible and understandable when looking at the second embodiment example according to FIG. 5.

FIG. 5 shows a schematic cross-sectional view, analogous to the representation of FIG. 1, of a second embodiment of a ship propulsion system S with a pump jet P. To prevent repetitions, with regard to all the components, their arrangement and effect, reference is made to the description of the first embodiment example according to FIGS. 1-4.

In contrast to the first embodiment example, in the second embodiment example, the rotor 2 is provided with a rotational axis B that is offset with respect to the control axis A of the pump jet P. The control axis A of the pump jet P, and the rotational axis b [sic] of the impeller or rotor 2 are, however, oriented mutually parallel.

Moreover, the deflection devices 12, to the extent that they are formed by the shaping of the inner space 11 of the diffuser or deflection housing 3 or of the pump housing G, in the present second embodiment example according to FIG. 5, are no longer of identical shape around the rotor 2, in comparison to the embodiment of the first embodiment example according to FIG. 1. The deflection devices 12 have an area 12 a with smaller cross-sectional profile and an area 12 b with larger cross-sectional profile; on the other hand, the cross-sectional profile in the entire area 12 c in the first embodiment example according to FIG. 1 is constant. A cross section which becomes larger towards the nozzles 9, in accordance with the area 12 b—with reference to the cross section in the area 12 a—of the second embodiment example according to FIG. 5 has, for example, a diffusion or diffuser effect.

It is precisely the offset arrangement of control axis A of the pump jet P and rotational axis B of the impeller I or rotor 2 that favors the design of the deflection devices 12 with the area 12 a having a smaller cross-sectional profile and with the area 12 b having a larger cross-sectional profile. However, the two aspects, on one hand, the offset of the axes, and, on the other hand, the irregular design of the deflection devices 12 in the inner space 11 of the diffuser or deflection housing 3 or of the pump housing G do not necessarily have to be combined.

In FIG. 6, in a schematic cross-sectional representation—analogous to the representation of FIGS. 1 and 5—a third embodiment example of a ship propulsion system S with a pump jet P is shown. To prevent repetition, with regard to all the components, their arrangement and effect, reference is made to the description of the first embodiment example according to FIGS. 1-4.

In contrast to the first embodiment example, in the third embodiment example, the rotor 2 presents a rotational axis B which is inclined with respect to the control A of the pump jet P. The control axis A of the pump jet P and the rotational axis B of rotor 2 intersect, however, at a point Z.

Moreover, in the third embodiment example according to FIG. 6 as well, as in the second embodiment example according to FIG. 5, the deflection devices 12, to the extent that they are formed by the shaping of the inner space 11 of the diffuser or deflection housing 3 or of the pump housing G, in comparison to the design in the first embodiment example according to FIG. 1, no longer present the same shape around the rotor 2, due to its inclined position. The deflection devices 12 again, as in the second example according to FIG. 5, have an area 12 a with smaller cross-sectional profile and an area 12 b with a larger cross-sectional profile; in contrast, as already explained above, the cross-sectional profile is constant in the entire area 12 c in the first embodiment example according to FIG. 1. A cross section which becomes larger towards the nozzles 9, in accordance with the area 12 b—with reference to the cross section in the area 12 a—of the second embodiment example according to FIG. 6 has, for example, a diffusion or diffuser effect.

It is precisely the inclined arrangement of rotational axis B of the impeller I or rotor 2 with respect to the control axis A of the pump jet P which favors the design of the deflection devices 12 with the area 12 a having a smaller cross-sectional profile and the area 12 b having a larger cross-sectional profile. In the design according to the third embodiment example, which is illustrated in FIG. 6, the areas 12 a and 12 b are, however, in terms of cross section not constant even in a peripheral section of the bead or ring shaped inner space 11 of the diffuser or deflection housing 3 or of the pump housing G, as is the case in the second embodiment example according to FIG. 5.

Moreover, in the third embodiment example as well, which is illustrated in FIG. 6, it is not necessary to combine, on the one hand, the inclination of the axis towards each other, and, on the other hand, an irregular design of the deflection devices 12 in the inner space 11 of the diffuser or deflection housing 3 or of the pump housing P.

The aspect that the rotational axis B of the impeller I or of the rotor 2, and the control axis A of the pump jet P are not in alignment, or in other words are not superposed or overlapping, can also be considered to be an independent invention, which is thus in itself worthy of invention protection, independently of the design of the ship propulsion system S with a pump jet P, which contains a pump housing G and a drive motor, where the drive motor is a magnet motor M or high-temperature superconducting motor integrated in the pump housing G. The nonaligned arrangement of the rotational axis B of the impeller I or rotor 2, and of the control axis A of the pump jet P is here the generally valid formulation, which covers the embodiment examples according to FIGS. 5 and 6, in which, in the second embodiment example, the rotor 2 is provided with a rotational axis B which is offset with respect to the control axis A of the pump jet P, or, in the third embodiment example, the rotor 2 presents a rotational axis B, which is inclined with respect to the control axis A of the pump jet P, where the control axis A of the pump jet P and the rotational axis B of the rotor 2 intersect particularly, but not necessarily, at a point Z.

In contrast to the described embodiments, one can use, as drive motor, instead of the magnet motor M or HTSC motor, alternatively also an electric motor E, such as, for example, particularly an asynchronous motor, synchronous motor or permanent magnet motor, which is placed on the pump housing G or partially integrated therein. Such an electric motor E is indicated only with broken lines in FIGS. 5 and 6 in connection with the second and third embodiment examples for clarification. If such an electric motor E is provided, it replaces the magnet motor M or the HTSC motor, which, in the first embodiment example according to FIG. 1, is provided as the only variant for the drive motor, and which, precisely in the second and third embodiment examples, can be provided in each case as the only drive motor. As indicated, the variants of a drive motor in the form of a magnet motor M or HTSC motor integrated in the pump housing G, on the one hand, and of an electric motor E placed on the pump housing G or partially integrated therein are alternatives, if the inventive aspect of the nonaligned axes, namely the rotational axis B of the impeller or rotor 2 and the control axis A of the pump jet P, is considered separately. When using an electric motor E as a drive motor placed on the pump housing G or integrated therein, force transferring parts, such as teeth, roller bearings and/or shafts are of course necessary, to ensure the rotatory connection between such a drive motor and the impeller of the pump jet P; however, this is part of the standard knowledge of a person skilled in the art, and to that extent not a component of the present invention, and also not part of the inventive aspect that the rotational axis b of the impeller or rotor 2 and the control axis A of the pump jet P are not in alignment.

The invention is illustrated merely as an example using the embodiment examples in the description and in the drawing, and it is not limited to those examples, rather it comprises all the variants, modifications, substitutions and combinations that the person skilled in the art can obtain from the available documents, particularly in the context of the claim and the general presentations in the introduction of this description as well as the description of the embodiment examples, and combine with his/her specialized knowledge as well as the prior art. In particular, all the characteristics and design possibilities of the invention and their embodiment examples can be combined. 

1. Ship propulsion system (S) with a pump jet (P), which contains a pump housing (G) and a drive motor, wherein a rotor (2) of an impeller of the pump jet (P) contains a rotational axis (B), which is not in alignment with a control axis (A) of the pump jet (P).
 2. Ship propulsion system (S) according to claim 1, wherein the rotational axis (B) of the rotor (2) is offset with respect to the control axis (A) of the pump jet (P).
 3. Ship propulsion system (S) according to claim 2, wherein the rotational axis (B) of the rotor (2) and the control axis (A) of the pump jet (P) are parallel.
 4. Ship propulsion system (S) according to claim 1, wherein the rotational axis (B) of rotor (2) and the control axis (A) of the pump jet (P) are mutually inclined.
 5. Ship propulsion system (S) according to claim 4, wherein the rotational axis (B) of the rotor (2) and the control axis (A) of the pump jet (P) intersect at a point.
 6. Ship propulsion system (S) according to claim 1, wherein the drive motor is an electric motor (E) which is placed on the pump housing (G) or partially integrated therein.
 7. Ship propulsion system (S) according to claim 6, wherein the electric motor (E) is an asynchronous motor, synchronous motor or permanent magnet motor.
 8. Ship propulsion system (S) according to claim 6 wherein between the electric motor (E) and the impeller, force transferring parts, such as teeth, roller bearings and/or shafts are provided.
 9. Ship propulsion system (S) according to claim 1, wherein the drive motor is a magnet motor (M) or a high-temperature superconducting motor integrated in the pump housing (G).
 10. Ship propulsion system (S) according to claim 9, wherein the pump jet (P) can be controlled all around.
 11. Ship propulsion system (S) according to claim 9 wherein the magnet motor (M) or high-temperature superconducting motor contains a rotor (2), which is a component of an impeller (I) of the pump jet (P).
 12. Ship propulsion system (S) according to claim 9, wherein the magnet motor (M) or high-temperature superconducting motor contains a stator (1), which is a component of a diffuser inner ring (D) of the pump jet (P).
 13. Ship propulsion system (S) according to claim 9, wherein the conveyance medium is also used particularly by itself also as lubricant and/or coolant.
 14. Ship propulsion system (S) according to claim 9, wherein the drive of the pump jet (P) is free of force transferring parts, such as teeth, roller bearings and/or shafts.
 15. Ship propulsion system (S) according to claim 1, wherein deflection devices (12, 12 a, 12 b, 12 c, 13) are provided, which are arranged and/or designed in an inner space (11) of the diffuser housing (3).
 16. Ship propulsion system (S) according to claim 15, wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) are arranged and/or designed in such a way that they eliminate turbulence from a water flow in the inner space (11) of the diffuser housing (3) and/or direct the water flow in such a way that water exits through a nozzle (9) of the pump jet (P) as much as possible without internal turbulence or in such a way that through individual nozzles (9 a, 9 b, 9 c) a desired quantity of water exits per unit of time, particularly the same amount of water per unit of time and/or to the extent possible without internal turbulence, to achieve an optimal thrust effect of the pump jet (P).
 17. Ship propulsion system (S) according to claim 15 wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) contain at least one shaping of the inner space (11) of the diffuser housing (3).
 18. Ship propulsion system (S) according to claim 17, wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) contain an area (12 c) having a constant cross-sectional profile of the inner space (11) of the diffuser housing (3).
 19. Ship propulsion system (S) according to claim 17, wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) contain an area (12 a) having a reduced cross-sectional profile of the inner space (11) of the diffuser housing (3).
 20. Ship propulsion system (S) according to claim 17, wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) contain an area (12 a) having an enlarged cross-sectional profile of the inner space (11) of the diffuser housing (3).
 21. Ship propulsion system (S) according to claim 15, wherein the deflection devices (12, 12 a, 12 b, 12 c, 13) contain at least one guide vane (13) in the inner space (11) of the diffuser housing (3). 